Lightning being mad at Snow, Hope towards Snow, then later Sazh towards Vanille, etc was the thing for most of the game. Only reasonable one is Lightning and Snow (also interestingly the only one with apologizes involved), the rest are a bit forced.
See this (Motomu Toriyama wanted things to be dramatic.)
For example, lets talk about Vanille - One thing SE did (if you carefully examine her choices and what actually happened) was make Vanille's choices actually reasonable (Fang was a huge part of why). The whole lying thing was needed because Fang was determined to save Vanille (complete their Focus) which Vanille disagreed with.
However the game and other character likes to make a big deal out of this and makes it seem like her actions are bad. One example is the Sazh + Vanille scene. Problem with the scene is that the video he was shown clearly shows that Vanille didn't do anything wrong (it was Fang who provoked the fal'Cie) but yet he overreacts in that scene.